Michael Stone confessed to fellow prison inmates details of the attack, which left her brain damaged and her mother and sister dead, the court heard. He also admitted getting sexual pleasure from smelling the wet swimming costumes which Josie and her sister Megan were carrying home from school that day.
Stone, 38, of Gillingham, Kent, denies murdering Lin Russell, 45, and Megan, 6, at Chillenden near Canterbury on 9 July 1996. He also denies the attempted murder of Josephine, known as Josie, who was then aged nine.
Maidstone Crown Court heard how Stone repeatedly told police he had no involvement in the killings which took place after he allegedly demanded money from Mrs Russell.
But in two separate conversations with inmates while he was in prison on remand, Stone referred to the murders which shocked the nation.
Ann Rafferty, QC, prosecuting, said Stone told a prisoner identified only as "Daly" how he had tied the Russells up with the wet towels the girls were carrying home from a swimming gala.
"He had smelt the swimming costumes and achieved his best ever orgasm," Miss Rafferty said.
In a 10 or 15-minute conversation with Daly, Stone spoke repeatedly of the Russells as "slags" and called them both "paupers" the court heard, in an apparent reference to Mrs Russell having no money with her. He described battering the Russells' heads as like "bashing an egg in".
Recounting what Stone allegedly told Daly, Miss Rafferty said: "One of them had tried to get away but didn't get far. Although he had wanted one of them to watch, she had closed her eyes so he had hit her again and she squirmed ... they had not had what he wanted."
In a bitter exchange with another inmate, Barry Thompson, Stone warned: "I made a mistake with her. I won't make the same mistake with you." Miss Rafferty suggested Stone was referring to Josie Russell, who had appeared dead but survived to be able to provide details of the attack.
Although there was no forensic evidence relating Stone directly to the crime, Miss Rafferty said the case against him rested on these conversations supported by circumstantial evidence. Even Stone himself had conceded he could see why people thought he looked like the E-fit image which was produced after the attack.
Two friends reported blood on Stone's clothing and tool box the day after the killing. And another friend, John Porter, told how Stone knew the remote rural area where the crime took place "like the back of his hand". Stone had spent some time in care there as a child.
The jury of eight women and four men heard that Lin Russell suffered at least 15 severe blows in a "sustained, vicious attack" to her head causing at least nine fractures. She appeared to have been tied wrist to wrist.
Megan, who had been tied around her neck to restrain her, had multiple fractures to her skull which was effectively split in two. Josie, who was blind-folded and tied to a tree with pipe, had to undergo surgery to repair damaged brain tissue and splintered bone.
The court heard how a woman driver Nicola Burthell, a potter, followed a beige Ford Escort down Cherry Garden Lane near where the attacks took place on the afternoon of 9 July.
She later produced an E-fit image of the driver which bore a resemblance to Stone. And although she failed to identify him as the driver at an identity parade a year after the killings, she did identify him as "very familiar".
Miss Rafferty said two people, Lawrence Calder and Sheree Batt, noticed Stone had bloodstained clothing when he visited them the day after the attack.
Miss Batt questioned him about the blood and he said he had been in a fight, although there was no trace of injury to his face.
Mr Calder thought Stone seemed "distracted, not himself" and noticed there was more blood on a hooded sweatshirt on the back seat of his car and splashed on tools in his tool box.
In a statement read to the court, Dr Shaun Russell told how he had last seen his wife alive before he set off for work at the University of Kent in Canterbury that morning.
"She had kissed me goodbye, which is unusual for us because we were normally in a rush," he said. He arrived home in the evening to find the house locked up and dark. He was surprised but decided something must have happened and proceeded to cook supper.
But Miss Rafferty said that as time went by, he grew anxious. He called police stations asking if there had been any accidents and then local hospitals with the same question. Eventually he reported his family missing and police arrived at 7.30 to begin a search.
At about a quarter past midnight, officers found Megan's swimming costume in Cherry Garden Lane, Chillenden, and 15 minutes later they came across the bodies of Lin and Megan and Josie with Lucy, the family dog.
"They all appeared to be dead," Miss Rafferty said, and a police officer was dispatched to break the news to Dr Russell. Only afterwards was Josie found to still have a pulse.
Dr Michael Parks, the police doctor who had been called to examine the body, carried her cradled in his arms to the car and she was rushed first to the Kent and Canterbury Hospital in Canterbury and then on to intensive care at King's College Hospital, London. "In spite of being seriously injured Josie made a recovery that no-one would have predicted," Miss Rafferty said.
No-one would pretend she would be able to give a lucid and coherent account of the attack but she had been able to recall details of what happened.
As the family was walking home from school in the neighbouring village of Goodnestone, a car had passed them. They walked on to find it slewed across the track before them.
"The man got out. He opened the rear door and from a shelf at the back took a hammer," Miss Rafferty said.
He wanted Mrs Russell to give him money. She said she had none but she would go home and get some for him. As he rejected the offer, Mrs Russell urged Josie to run, but the man caught her and brought her back.
She was tied to a tree while her mother was bound with strips torn from their swimming towels.
Josie, blindfolded, heard her mother's cries as she was struck by a hammer. She too was beaten and more than eight hours passed before she was found clinging to life.
The case continues.Reuse content